Turkey will reopen its Incirlik air base to U.S. planes, used to attack Islamic State, following an attempted coup, the Pentagon said on Sunday.

"After close coordination with our Turkish allies, they have reopened their airspace to military aircraft. As a result, counter-ISIL coalition air operations at all air bases in Turkey have resumed," a Pentagon statement said.

Turkey, a major U.S. ally, has allowed the United States to use the air base in Incirlik to launch attacks against the militant group. Those air operations were temporarily halted following the coup attempt on Friday.

Secretary of State John Kerry said on CNN's "State of the Union" that he had spoken with Turkey's foreign minister three times on Saturday.

"They assure me that there will be no interruption of our counter-ISIL efforts," Kerry said, using an acronym to refer to the Islamic State.

Kerry said that the difficulty for U.S. planes accessing Incirlik may have been a result of planes flown in support of the coup using the air base to refuel.

On NBC's "Meet the Press" on Sunday, Kerry was asked if Turkey's president Tayyip Erdogan would use the coup attempt to seize more power.

Kerry said such a move by Erdogan would be a challenge to his relationship with Europe, with NATO and others.

"We have urged them not to reach out so far that they are creating doubts about their commitment to the democratic process," he said.

Erdogan has blamed his rival, Fethullah Gulen, for masterminding the coup attempt. Gulen, who is currently living in Pennsylvania, has denied any involvement.

Kerry said he had no evidence at this time that Gulen was behind the plot to seize power from Erdogan, but he urged Turkish authorities to compile evidence as rapidly as possible so the United States can evaluate whether Gulen should be extradited to Turkey.